From 899a04f5ed61c3db7a2bd84957ecf530c09fd05a Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Wed, 11 Mar 2020 11:04:59 -0300 Subject: [PATCH] Avoid duplicates in ALTER ... DEPENDS ON EXTENSION If the command is attempted for an extension that the object already depends on, silently do nothing. In particular, this means that if a database containing multiple such entries is dumped, the restore will silently do the right thing and record just the first one. (At least, in a world where pg_dump does dump such entries -- which it doesn't currently, but it will.) Backpatch to 9.6, where this kind of dependency was introduced. Reviewed-by: Ibrar Ahmed, Tom Lane (offlist) Discussion: https://postgr.es/m/20200217225333.GA30974@alvherre.pgsql --- src/backend/catalog/pg_depend.c | 43 +++++++++++++++++++ src/backend/commands/alter.c | 7 ++- src/include/catalog/dependency.h | 1 + .../expected/test_extdepend.out | 2 + .../test_extensions/sql/test_extdepend.sql | 2 + 5 files changed, 54 insertions(+), 1 deletion(-) diff --git a/src/backend/catalog/pg_depend.c b/src/backend/catalog/pg_depend.c index f9af245eec0..596dafe19c8 100644 --- a/src/backend/catalog/pg_depend.c +++ b/src/backend/catalog/pg_depend.c @@ -648,6 +648,49 @@ getExtensionOfObject(Oid classId, Oid objectId) return result; } +/* + * Return (possibly NIL) list of extensions that the given object depends on + * in DEPENDENCY_AUTO_EXTENSION mode. + */ +List * +getAutoExtensionsOfObject(Oid classId, Oid objectId) +{ + List *result = NIL; + Relation depRel; + ScanKeyData key[2]; + SysScanDesc scan; + HeapTuple tup; + + depRel = table_open(DependRelationId, AccessShareLock); + + ScanKeyInit(&key[0], + Anum_pg_depend_classid, + BTEqualStrategyNumber, F_OIDEQ, + ObjectIdGetDatum(classId)); + ScanKeyInit(&key[1], + Anum_pg_depend_objid, + BTEqualStrategyNumber, F_OIDEQ, + ObjectIdGetDatum(objectId)); + + scan = systable_beginscan(depRel, DependDependerIndexId, true, + NULL, 2, key); + + while (HeapTupleIsValid((tup = systable_getnext(scan)))) + { + Form_pg_depend depform = (Form_pg_depend) GETSTRUCT(tup); + + if (depform->refclassid == ExtensionRelationId && + depform->deptype == DEPENDENCY_AUTO_EXTENSION) + result = lappend_oid(result, depform->refobjid); + } + + systable_endscan(scan); + + table_close(depRel, AccessShareLock); + + return result; +} + /* * Detect whether a sequence is marked as "owned" by a column * diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c index 1cb84182b05..11db9bfe922 100644 --- a/src/backend/commands/alter.c +++ b/src/backend/commands/alter.c @@ -433,6 +433,7 @@ ExecAlterObjectDependsStmt(AlterObjectDependsStmt *stmt, ObjectAddress *refAddre ObjectAddress address; ObjectAddress refAddr; Relation rel; + List *currexts; address = get_object_address_rv(stmt->objectType, stmt->relation, (List *) stmt->object, @@ -462,7 +463,11 @@ ExecAlterObjectDependsStmt(AlterObjectDependsStmt *stmt, ObjectAddress *refAddre if (refAddress) *refAddress = refAddr; - recordDependencyOn(&address, &refAddr, DEPENDENCY_AUTO_EXTENSION); + /* Avoid duplicates */ + currexts = getAutoExtensionsOfObject(address.classId, + address.objectId); + if (!list_member_oid(currexts, refAddr.objectId)) + recordDependencyOn(&address, &refAddr, DEPENDENCY_AUTO_EXTENSION); return address; } diff --git a/src/include/catalog/dependency.h b/src/include/catalog/dependency.h index 0cd6fcf027f..ab5e92bdc6f 100644 --- a/src/include/catalog/dependency.h +++ b/src/include/catalog/dependency.h @@ -207,6 +207,7 @@ extern long changeDependenciesOn(Oid refClassId, Oid oldRefObjectId, Oid newRefObjectId); extern Oid getExtensionOfObject(Oid classId, Oid objectId); +extern List *getAutoExtensionsOfObject(Oid classId, Oid objectId); extern bool sequenceIsOwned(Oid seqId, char deptype, Oid *tableId, int32 *colId); extern List *getOwnedSequences(Oid relid); diff --git a/src/test/modules/test_extensions/expected/test_extdepend.out b/src/test/modules/test_extensions/expected/test_extdepend.out index 11e441ddd37..40533e90de3 100644 --- a/src/test/modules/test_extensions/expected/test_extdepend.out +++ b/src/test/modules/test_extensions/expected/test_extdepend.out @@ -47,6 +47,8 @@ SELECT * FROM test_extdep_commands \gexec CREATE INDEX e ON a (a1) ALTER INDEX e DEPENDS ON EXTENSION test_ext5 RESET search_path +-- A dependent object made dependent again has no effect +ALTER FUNCTION test_ext.b() DEPENDS ON EXTENSION test_ext5; -- make sure we have the right dependencies on the extension SELECT deptype, p.* FROM pg_depend, pg_identify_object(classid, objid, objsubid) AS p diff --git a/src/test/modules/test_extensions/sql/test_extdepend.sql b/src/test/modules/test_extensions/sql/test_extdepend.sql index cf44145dcb3..cc170ab7097 100644 --- a/src/test/modules/test_extensions/sql/test_extdepend.sql +++ b/src/test/modules/test_extensions/sql/test_extdepend.sql @@ -27,6 +27,8 @@ COPY test_extdep_commands FROM stdin; SELECT * FROM test_extdep_commands; -- First, test that dependent objects go away when the extension is dropped. SELECT * FROM test_extdep_commands \gexec +-- A dependent object made dependent again has no effect +ALTER FUNCTION test_ext.b() DEPENDS ON EXTENSION test_ext5; -- make sure we have the right dependencies on the extension SELECT deptype, p.* FROM pg_depend, pg_identify_object(classid, objid, objsubid) AS p